<template>
  <div>
    <!-- 评论列表 -->
    <div class="cmt-list" :class="{ 'art-cmt-container-1': !isShowCmtInput, 'art-cmt-container-2': isShowCmtInput}">
      <div>
        <van-list :immediate-check="false" v-model="loading" :finished="finished" finished-text="没有更多了" @load="onLoad">
          <!-- 评论的 Item 项 -->
          <div class="cmt-item" v-for="obj in commentList" :key="obj.com_id">
            <!-- 头部区域 -->
            <div class="cmt-header">
              <!-- 头部左侧 -->
              <div class="cmt-header-left">
                <img :src="obj.aut_photo" alt="" class="avatar">
                <span class="uname">{{obj.aut_name}}</span>
              </div>
              <!-- 头部右侧 -->
              <div class="cmt-header-right">
                <van-icon @click="loveFn(obj,true)" v-if="obj.is_liking === true" name="like" size="16" color="red" />
                <van-icon @click="loveFn(obj,false)" v-else name="like-o" size="16" color="gray" />
              </div>
            </div>
            <!-- 主体区域 -->
            <div class="cmt-body">
              {{obj.content}}
            </div>
            <!-- 尾部区域 -->
            <div class="cmt-footer">{{timeAgo(obj.pubdate)}}</div>
          </div>
        </van-list>
      </div>
    </div>

    <div>
      <!-- 底部添加评论区域 - 1 -->
      <div class="add-cmt-box van-hairline--top" v-if="isShowCmtInput === false">
        <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
        <div class="ipt-cmt-div" @click="isShowCmtInput = true">发表评论</div>
        <div class="icon-box">
          <van-badge :content="totalCount === 0 ? '' : totalCount" :max="99">
            <van-icon @click="moveFn" name="comment-o" size="0.53333334rem" />
          </van-badge>
          <van-icon name="star-o" size="0.53333334rem" />
          <van-icon name="share-o" size="0.53333334rem" />
        </div>
      </div>

      <!-- 底部添加评论区域 - 2 -->
      <div class="cmt-box van-hairline--top" v-else>
        <textarea v-model.trim="comText" @blur="blurFn" v-fofo placeholder="友善评论、理性发言、阳光心灵"></textarea>
        <van-button @click="sendFn" type="default" :disabled="comText.length > 0 ? false : true">发布</van-button>
      </div>
    </div>
  </div>
</template>

<script>
import { commentListAPI, commentLikingAPI, commentDisLikingAPI, sendCommentAPI } from '@/api/index.js'
import { timeAgo } from '@/utils/date.js'

export default {
  data () {
    return {
      commentList: [],
      isShowCmtInput: false,
      totalCount: 0,
      comText: '',
      offset: null,
      loading: false,
      finished: false,
      lastId: null // 分页
    }
  },
  methods: {
    timeAgo,
    async loveFn (obj, flag) {
      if (flag) {
        obj.is_liking = false
        await commentDisLikingAPI({
          comId: obj.com_id
        })
      } else {
        obj.is_liking = true
        await commentLikingAPI({
          comId: obj.com_id
        })
      }
    },
    // 评论滑动
    moveFn () {
      // 真实DOM都在document(所以不再一个vue文件内), 也是可以获取的
      // 原生标签.scrollIntoView,让原生的标签滚动到屏幕的最上面
      document.querySelector('.like-box').scrollIntoView({
        behavior: 'smooth'
      })
    },
    async sendFn () {
      const { data: res } = await sendCommentAPI({
        artId: this.$route.query.art_id,
        content: this.comText
      })
      // 保存新评论对象到数组中
      this.commentList.unshift(res.data.new_obj)
      // 数量+1
      this.totalCount++
      // 成功后, 清除输入框内容
      this.comText = ''
      this.moveFn()
    },
    blurFn () {
      // 点击发布按钮，发现点击事件不执行-排除代码问题
      // 原因：高的评论容器-在页面点击发布的一瞬间，输入框失去了焦点，被v-if和v-else移出了整个标签
      // 导致点击事件没来及执行
      // 解决：失去焦点是变量值，在最后在执行
      setTimeout(() => {
        this.isShowCmtInput = false
      }, 0)
    },
    async onLoad () {
      if (this.commentList.length > 0) {
        // 请求下一页数据
        const { data: res } = await commentListAPI({
          artId: this.$route.query.art_id,
          offset: this.lastId
        })
        this.commentList = [...this.commentList, ...res.data.results]
        this.totalCount = res.data.total_count
        this.lastId = res.data.last_id

        if (res.data.last_id === null) {
          this.finished = true
        }

        this.loading = false
      } else {
        this.loading = false
      }
    }
  },
  async created () {
    const { data: res } = await commentListAPI({
      artId: this.$route.query.art_id
    })
    this.commentList = res.data.results
    this.totalCount = res.data.total_count
    this.lastId = res.data.last_id

    if (res.data.results.length === 0) {
      this.finished = true
    }
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
